Ask Mr. Smarty Plants

Fremontodendron californicum (California flannelbush) is native to California and Arizona, but is pretty particular about where it grows, preferring dry, well-drained granitic soil. It has low water needs, can grow in hot sun or part shade, and is fast-growing to 5 ft. In this USDA Profile of the flannel bush, it appears that your area is virtually the only place in Southern California where it is not native. That doesn't necessarily indicate what is wrong with it, as the sappy material at the base sounds more like some kind of disease. This Calfoto website, on the other hand, shows that there is available a Herbarium example from Orange County. We learned that it survives only a short time in clay soils under garden conditions. However, a plant placed where it is not comfortable is more likely to be susceptible to pests and diseases, so we'll try to find out what might be causing your problem. 

From Wikipedia (not necessarily the last word in accuracy) we extracted this quotation on flannel bush:

"The bark bears a gooey sap that was once used as a topical remedy for mucous membrane irritation and for gastrointestinal upset. However, the hairs covering the leaves are easily brushed off and are a skin and eye irritant."

Other things about this plant we discovered by searching on the Internet include that it should not be watered in the middle of the day, as water on hot roots can be fatal. Another piece of information was that flannel bush is subject to sudden collapse and death, even if they have been growing and flowering well.

We realize this doesn't really solve your problem. From the facts collected, we are thinking that perhaps you have a clay soil, as opposed to a well-draining soil; this plant cannot tolerate wet feet. The sappy discharge may very well be a normal feature of the plant's development. We really can't recommend a treatment, since we don't know exactly what is wrong. If you want to try to save the plant, water infrequently, not with a sprinkler system. When it cools off in the fall, try to get some organic matter, like compost, into the soil around it to encourage better drainage. If it dies and you wish to replace it, you should first carefully consider your soil and whether it is appropriate to the plant. And don't fertilize, now or later, it grows best in poor soils. 

Fremontodendron californicum

Fremontodendron californicum

Fremontodendron californicum

Fremontodendron californicum